The goal of this project is to continue to develop improved antibody- based treatment protocols for B cell lymphoma. MoAbs to be used include murine anti-idiotype (Id) antibodies, including private (PID) and shared (SID) idiotypes; murine anti-CD20 (MualphaCD20) pan B; and chimeric human/mouse anti-CD20 (ChalphaCD20). The emphasis of our studies will continue to be the use of 90Yttrium-labeled murine MoAbs. However, prior to the testing of 90Y-ChalphaCD20, we will study unlabeled ChalphaCD20 to determine its biological activity and biodistribution in vivo. The rationale for studying 90Y-anti Id relates to the (1) tumor specificity of anti-PID (or tumor selectivity for anti-SID), (2) the inherent radiosensitivity of lymphoma, (3) the superior therapeutic characteristics of 90Y over 130I, and (4) the potential for eradicating Id-negative variant cells in the tumor which are known to escape therapy with unlabeled anti-Id. Patients who have an "idiotype match" with the available panel of anti-SIDs or for whom an anti-PID has been produced will continue to be treated on our phase I/II trial of escalating doses of 90Y anti-Id. Patients who do not have an idiotype match or for whom an anti-PID is not available at the time of treatment will enter one of the anti-pan B trials.